Most thermowells are machined from a single solid material. While use of such a single material is advantageous for durability and accuracy in thermal measurements, single piece thermowells are expensive to manufacture, particularly since customers desire the ability to select the length of the thermowell for their application, and to utilize a desired well construction. Accordingly, large numbers of thermowells must be maintained in inventory by the manufacturer to satisfy the various needs of the customer.
Friction welding using a pre-determined stored energy in a rotating mass or flywheel has been used to form a weld. The flywheel allows for more precise welds and also uses the minimum amount of energy to achieve the needed result. The flywheel can be “tuned” to the optimum point when the weld friction overcomes the remaining inertia motion of the flywheel. This method produces a joint that is as strong as or better than the base metal and will not be susceptible to cracking or being fatigued by the extreme forces. Friction welding machine are disclosed in U.S. Pat. Nos. 3,134,278 and 3,235,162.
The disadvantages of the prior art are overcome by the present invention, an improved modular thermowell is hereinafter disclosed.